A device obtains a signal representative of objects on a touch surface of a multi-touch sensing apparatus and executes a method for extracting touch data from the signal. The method operates in a sequence of detection frames. Each detection frame comprises the steps of: obtaining (300) the signal; processing (301) the signal for identifying touches; determining (302) a set of identified touches and touch data for the set of identified touches; and outputting (303) the touch data. At least one of the steps of processing (301) and determining (302) includes a prioritization that actively favors certain touches to be identified and included in the set of identified touches, respectively. Temporal prioritization favors a touch that corresponds to a previous touch, which is identified in one or more preceding detection frames. Spatial prioritization favors a touch that is located within at least one predefined subarea on the touch surface. The prioritization enables the touch data to be generated in way that is predictable, consistent and in accordance with user expectations within a general or specific context.
Legal claims defining the scope of protection. Each claim is shown in both the original legal language and a plain English translation.
1. A method for extracting data from a multi-touch sensing apparatus, said method operating in a sequence of detection frames, at least one detection frame among the sequence of detection frames comprising: obtaining at least one signal representative of objects on a touch surface of the multi-touch sensing apparatus; processing said at least one signal to identify touches; determining a set of identified touches and touch data for the set of identified touches; and outputting the touch data; wherein each of the detection frames includes a spatial prioritization, the spatial prioritization based on a previous touch, which is identified by the processing performed in one or more preceding detection frames; and wherein the processing said at least one signal to identify touches includes comparing a spatial distribution of signal values of the at least one signal with corresponding threshold signal values, using the spatial prioritization to estimate a location of a touch corresponding to the previous touch, and locally changing the corresponding threshold signal values based on the estimated location.
A method for a multi-touch device to identify and track touches on its screen, operating in a series of cycles called "detection frames". In each frame, the device gets a signal representing touches, analyzes the signal to find potential touches, determines a set of actual touches from the potential ones, and outputs the touch data (location, pressure, etc.). A key aspect is spatial prioritization: if a touch was identified in a previous frame, the system expects it to be near its old location. When analyzing the signal in the current frame, the system lowers the threshold needed to identify a touch near the previously identified location, which makes it more likely to re-identify the same touch if it is still present. This is done by comparing the signal strength at different locations to threshold values, adjusting those thresholds near where the touch was last seen.
2. The method of claim 1 , wherein the processing operates to promote identification of the touch in said at least one signal.
The method described previously, where the system expects touches to persist near their last known locations, also emphasizes re-identifying these touches in the signal. This means the processing actively boosts the likelihood of identifying the touch based on its previous location, not just lowering the threshold, but enhancing signal features near that location if they are observed.
3. The method of claim 1 , wherein the processing further comprises: identifying a signal feature in said at least one signal based on the estimated location of the touch.
In the previously described multi-touch method, after estimating a touch's location based on past data, the system specifically looks for a particular signal "feature" at that location. This helps to confirm that a real touch is present, instead of just noise.
4. The method of claim 3 , wherein the signal feature is a local change in signal values of a projection signal; and the signal values correspond to transmitted energy on a plurality of detection lines across the touch surface.
Continuing from the feature-based touch identification, the "signal feature" being searched for is a local change in signal strength. The device uses projected energy (e.g., infrared light) across detection lines on the touch surface. The signal values represent the amount of energy detected on these lines. The system searches for a change (increase or decrease) in this energy near the touch's predicted location.
5. The method of claim 3 , wherein the signal feature corresponds to a local change in signal values in a distribution of an energy-related parameter within at least part of the touch surface.
Instead of using specific detection lines, the "signal feature" that helps identify touches is a local change in an energy-related characteristic (e.g., infrared light intensity, capacitance) within a region of the touch surface near the predicted location of the touch. It considers changes in energy distribution across the touch surface.
6. The method of claim 1 , wherein the signal values are included in said at least one signal.
In the original method for multi-touch data extraction, the signal values that are used to identify and track touches are directly part of the signal that the device reads from the touch screen's sensors. This means raw sensor data, such as voltage levels or light intensities, are used to locate potential touches.
7. The method of claim 1 , wherein the signal values are included in a distribution of an energy-related parameter within at least part of the touch surface, said distribution being obtained based on said at least one signal.
The signal values used for touch identification aren't necessarily directly from the sensor. Instead, the touch data is found using a distribution of energy-related characteristics (e.g., infrared light intensity, capacitance) across the touch surface. This distribution is calculated from the original sensor signal.
8. The method of claim 1 , wherein the processing further comprises: obtaining, based on said at least one signal, a distribution of an energy-related parameter within at least part of the touch surface; identifying a set of local extrema in the distribution; sequentially processing the set of local extrema for determining the touch data; and favoring one or more local extrema in the set of local extrema.
The method of extracting touch data from a multi-touch screen involves obtaining a distribution of an energy-related parameter (e.g. light intensity) across the touch surface. Then, it identifies local peaks (extrema) in this distribution. These peaks are potential touch locations. The method then processes these potential touch locations sequentially, and emphasizes certain local peaks over others.
9. The method of claim 1 , wherein the processing further includes identifying a number of touches based on said at least one signal; and the determining includes selecting the set of identified touches as a subset of said identified number of touches.
The method of extracting touch data from a multi-touch screen involves identifying a number of potential touches based on a signal. Then, it selects a subset of these potential touches as the "identified" touches. This means not every detected signal peak will be reported as a valid touch.
10. The method of claim 9 , wherein the set of identified touches is limited to a predefined maximum number of touches.
Building on the previous method of extracting touch data, the number of touches that the system reports is capped at a maximum limit. Even if the device detects more potential touches, it will only output data for a certain number.
11. The method claim 9 , wherein the processing further comprises: determining age data for each of the identified touches, the age data representing a number of preceding detection frames in which a touch is deemed to be identified; and wherein said set of identified touches is selected among the identified number of touches based on the age data.
The previously described method of selecting a subset of touches also considers the "age" of each potential touch. The "age" is the number of previous frames the touch has been tracked for. The system prioritizes older touches, so those that have been continuously tracked are more likely to be included in the final set of touches.
12. The method of claim 1 , further comprising: sequentially applying different prioritization criteria to determine the set of identified touches.
The touch data extraction method uses multiple prioritization criteria applied in sequence to determine the final set of identified touches. For example, it could first prioritize touches near previous locations and then prioritize older touches within that set.
13. The method of claim 1 , further comprising: accessing a history list including location data and age data of touch traces, wherein each of the touch traces represents a corresponding previous touch, the location data for a touch trace among the touch traces represents a most recent location of the corresponding previous touch on the touch surface, and the age data for the touch trace among the touch traces represents the number of detection frames in which the corresponding previous touch has been identified; and wherein the determining determines the set of identified touches based on at least the location data in the history list.
The method for extracting touch data from a multi-touch screen maintains a "history list" of touch traces. Each trace contains the location and age of a previously identified touch. The location data is the touch's most recent position on the screen, and the age is how many frames the touch has been tracked for. When determining the set of identified touches, the system uses at least the location data from this history list to prioritize touches that match existing traces.
14. The method of claim 13 , further comprising: matching said set of identified touches for a current detection frame to the touch traces in the history list; and updating the history list based on the matching.
The method of maintaining a history of touch traces involves comparing the touches identified in the current frame to the traces in the history list. If a match is found (e.g., a current touch is close to a previous touch location), the history list is updated with the new location and the touch's age is incremented.
15. A non-transitory computer-readable storage medium comprising computer code which, when executed on a data-processing system, causes the data-processing system to carry out the method of claim 1 .
A non-transitory computer-readable storage medium (e.g., a flash drive, hard drive) contains instructions that, when executed by a computer, cause the computer to perform the multi-touch data extraction method described in claim 1. This method uses spatial prioritization based on previous touch locations to improve touch tracking.
16. The method of claim 1 , wherein the spatial prioritization for a detection frame, in the sequence of detection frames, provides spatial information regarding peaks having been identified as touches in one or more previous detection frames in the sequence of detection frames.
The spatial prioritization technique provides spatial information about peaks in the touch sensor data that have been previously identified as touches. The method keeps track of the location of touches from one or more previous frames and uses this information to help identify the same touches in the current frame.
17. A device for generating touch data, said device configured to operate in a sequence of detection frames, and said device comprising: an input; and one or more processors connected to said input, the one or more processors configured to execute computer-readable instructions such that the one or more processors are configured to in at least one detection frame obtain, via said input, at least one signal representative of objects on a touch surface of a multi-touch sensing apparatus; process said at least one signal to identify touches; determine a set of identified touches and touch data for the set of identified touches; and output said touch data; wherein each of the detection frames includes a spatial prioritization, the spatial prioritization based on a previous touch, which is identified by the processing performed in one or more preceding detection frames; and wherein the one or more processors are configured to execute the computer-readable instructions such that the one or more processors are further configured to process said at least one signal to identify the touches by comparing a spatial distribution of signal values of the at least one signal with corresponding threshold signal values, using the spatial prioritization to estimate a location of a touch corresponding to the previous touch, and locally changing the corresponding threshold signal values based on the estimated location.
A device designed to generate touch data includes an input (e.g., a connection to a touch sensor) and one or more processors. The processors execute instructions to: Obtain a signal representing touches on a multi-touch screen. Process the signal to identify touches. Determine a set of identified touches and output the touch data. The key feature is spatial prioritization, where previous touch locations influence current touch identification. The processor compares signal values to thresholds, estimating touch location based on prior data and adjusting thresholds accordingly.
18. A multi-touch sensing apparatus, comprising: a touch surface, a plurality of sensors arranged within and/or around the touch surface and adapted to generate at least one signal representative of objects on the touch surface, and the device of claim 17 .
A multi-touch sensing apparatus includes a touch surface, sensors to generate a signal representing touches, and a touch data generation device. The touch data generation device is configured to operate in a sequence of detection frames, and is configured to: obtain, via an input, at least one signal representative of objects on a touch surface of a multi-touch sensing apparatus; process said at least one signal to identify touches; determine a set of identified touches and touch data for the set of identified touches; and output said touch data; wherein each of the detection frames includes a spatial prioritization, the spatial prioritization based on a previous touch, which is identified by the processing performed in one or more preceding detection frames; and wherein the one or more processors are configured to execute the computer-readable instructions such that the one or more processors are further configured to process said at least one signal to identify the touches by comparing a spatial distribution of signal values of the at least one signal with corresponding threshold signal values, using the spatial prioritization to estimate a location of a touch corresponding to the previous touch, and locally changing the corresponding threshold signal values based on the estimated location.
19. The device of claim 17 , wherein the spatial prioritization for a detection frame, in the sequence of detection frames, provides spatial information regarding peaks having been identified as touches in one or more previous detection frames in the sequence of detection frames.
The device which generates touch data, uses a spatial prioritization technique to provide spatial information about signal peaks previously recognized as touches. The method maintains a record of past touch locations and utilizes this to improve the recognition of these touches in subsequent frames.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
October 13, 2015
July 18, 2017
Browse 5M+ US patents with plain-English claim translations and AI-generated analysis.